The United States has long resisted reckoning with its past atrocities. In recent years, however, a full-fledged "politics of regret" has finally coalesced to challenge canonical narratives of national innocence and exceptionalism. In The Reverberating Past, Christina Simko chronicles how the politics of regret emerged out of a pervasive trauma culture that supplanted a future-oriented faith in progress. At new sites of racial reckoning, such as the Alabama-based National Memorial for Peace and Justice, designers have fused the language of trauma and terror with a lineage of Black thought that has consistently testified to the enduring presence of the past, including the afterlives of slavery, in the United States. Yet as the politics of regret solidified, a populist nostalgia has also arisen to contest the boundaries of the past, similarly rooted in trauma culture. Instead of mourning the reverberating legacies of violence or vowing to eradicate them, populist nostalgia promises to restore a lost past, often through the very symbols and structures that have perpetuated racial violence and inequality.By exploring the modern legacy of trauma in U.S. memorial sites and museums, The Reverberating Past reveals what is at stake in the tense—and, at times, violent—confrontation between nostalgia and regret, and how representations of the past shape our capacity to imagine alternative futures.